1. Field of the Invention
The present invention relates to an information processing apparatus, a color/monochrome determination method therefor, and a program for implementing the method.
2. Description of the Related Art
There has conventionally been proposed a technique called the automatic color/monochrome switching, in which color/monochrome determination is performed on data to be printed and when there exists only monochrome data within a page, the data of the page is processed as monochrome data.
For example, when the printing speed of a printer is different between color printing and monochrome printing, or when the billing amount is different between color printing and monochrome printing, the above-mentioned technique is essential because it enables users to enjoy optimal running costs and printing speed.
Further, there has already been disclosed a prior art printing system to which the color/monochrome determination is applied (see e.g. Japanese Laid-Open Patent Publication (Kokai) No. 10-285421).
The main object of execution of the color/monochrome determination in the prior art printing system is to enable a printer engine to operate at the highest possible speed.
For this reason, a printer driver carries out a process for analyzing drawing information input from an application, and determining, if characters as a print object have color information set therefor, that the characters are “in color” (to be printed in color), whereas if not, that they are “in monochrome” (to be printed in monochrome).
Insofar as character codes are concerned, the conventional printer driver carries out the color/monochrome determination by only referring to the color attribute of each character.
However, characters include not only numerals, symbols, kanji characters, and like characters, which are actually drawn, but also a space character, and like characters, which have nothing to be drawn but are treated as characters since they are input in the form of character codes.
Therefore, if a character as a printing object includes such a character, which is not to be drawn but has color information set therefor, the conventional printer driver recognizes the character attribute of the character as “color” even though the print data provides an apparently “monochrome” print when actually printed. Therefore, the color processing mode for the page containing the character is determined to be set to “color”.
For example, assuming that a character string “AB C” has a space character between “B” and “C”, as shown in FIG. 5A, and the space character has a color setting of red, the character data of this character string is determined to be “in color”.
Further, when an external character is to be printed, it is impossible to determine from its character code whether the character is actually drawn.